Upvote:3
Well-developed Buddhist samatha-vipassana meditation cleanses the body & mind from mental impurities such as greed, lust, hatred, anger, delusion, etc. Also, to practise samatha-vipassana successfully requires lots of self-love or self-compassion. Thus, when the true results of samatha-vipassana meditation are developed, what will remain is bliss & love. In summary, when unwholesome emotions are cleansed, what naturally will remain are wholesome emotions.
Therefore, one does not really need to complement samatha-vipassana with other techniques to develop those qualities. Often, sympathetic joy, loving kindness, compassion, etc, need to be developed when there are hindrances to samatha-vipassana. But if there are no hindrances to concentration, those qualities will be included in the natural results of samatha-vipassana.
Upvote:5
Your concern is based on invalid definition of Vipassana/Vipashyana. "Watching equanimously your bodily sensations" is not what Buddha meant by insight meditation. Insight meditation is rigorous introspection of one's mental processes seeking answers to questions like:
Now, this is vipashyana - sitting and looking at one's mindstream in order to get answers to these questions.
Once you get some answers to most of the above - and with your new perspective you look back at the state of humanity -- you suddenly find yourself having the very same loving kindness, compassion, and sympathetic joy arising quite spontaneously ;)